emulator: NeoCD
type: libretro
core_classification: pure_libretro
source: "https://github.com/libretro/neocd_libretro"
upstream: "https://github.com/libretro/neocd_libretro"
profiled_date: "2026-03-24"
core_version: "2022"
display_name: "SNK - Neo Geo CD (NeoCD)"
cores:
  - neocd
systems:
  - snk-neogeo-cd

notes: |
  Complete rewrite of NeoCD in C++11. Scans {system_dir}/neocd/ for any .rom
  or .bin file, also inside .zip archives (src/libretro_bios.cpp:69-105,
  src/path.cpp:6 NEOCD_SYSTEM_SUBDIR = "neocd").

  BIOS identified by binary pattern matching at fixed ROM addresses, not by
  filename (src/bios.cpp:167-206). Files are auto byte-swapped if needed
  (src/bios.cpp:148-160). Files smaller than 524288 bytes are skipped
  (src/libretro_bios.cpp:42).

  Three hardware families detected: Front Loader, Top Loader, CDZ. Modified
  variants recognized: SMKDan 0.07, SMKDan 0.07b, Universe BIOS 3.2,
  Universe BIOS 3.3 (src/bios.h:11-27). Any single valid BIOS is sufficient;
  selection via core options dropdown sorted alphabetically.

  Y-ZOOM ROM (ng-lo.rom / 000-lo.lo) listed in .info but generated
  algorithmically, never loaded from file (src/memory.cpp:223-253
  generateYZoomData, CRC32 E09E253C). These are phantom .info entries.

  .info firmware_count=12 but 2 are phantoms (Y-ZOOM), effective count=10.
  .info lists uni-bioscd.rom as "Universe BIOS 3.2" but SHA1 matches
  Universe BIOS 3.3 (confirmed by GitHub README).

files:
  # --- Front Loader family ---

  - name: neocd_f.rom
    path: "neocd/neocd_f.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Front Loader BIOS (big-endian, NeoCD naming)"
    source_ref: "src/bios.cpp:59 FRONT_LOADER_SEARCH_PATTERN at 0xC0006C"

  - name: front-sp1.bin
    path: "neocd/front-sp1.bin"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Front Loader BIOS (little-endian, MAME naming)"
    source_ref: "src/bios.cpp:59 FRONT_LOADER_SEARCH_PATTERN, src/bios.cpp:148-160 autoByteSwap"

  - name: neocd_sf.rom
    path: "neocd/neocd_sf.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Front Loader BIOS, SMKDan 0.07b"
    source_ref: "src/bios.cpp:62 SMKDANBETA_FRONT_SEARCH_PATTERN at 0xC00004"

  # --- Top Loader family ---

  - name: neocd_t.rom
    path: "neocd/neocd_t.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Top Loader BIOS (big-endian, NeoCD naming)"
    source_ref: "src/bios.cpp:60 TOP_LOADER_SEARCH_PATTERN at 0xC0006C"

  - name: top-sp1.bin
    path: "neocd/top-sp1.bin"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Top Loader BIOS (little-endian, MAME naming)"
    source_ref: "src/bios.cpp:60 TOP_LOADER_SEARCH_PATTERN, src/bios.cpp:148-160 autoByteSwap"

  - name: neocd_st.rom
    path: "neocd/neocd_st.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Top Loader BIOS, SMKDan 0.07b"
    source_ref: "src/bios.cpp:63 SMKDANBETA_TOP_SEARCH_PATTERN at 0xC00004"

  # --- CDZ family ---

  - name: neocd_z.rom
    path: "neocd/neocd_z.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "CDZ BIOS (big-endian, NeoCD naming)"
    source_ref: "src/bios.cpp:61 CDZ_SEARCH_PATTERN at 0xC0006C"

  - name: neocd.bin
    path: "neocd/neocd.bin"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "CDZ BIOS (little-endian, MAME naming)"
    source_ref: "src/bios.cpp:61 CDZ_SEARCH_PATTERN, src/bios.cpp:148-160 autoByteSwap"

  - name: neocd_sz.rom
    path: "neocd/neocd_sz.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "CDZ BIOS, SMKDan 0.07b"
    source_ref: "src/bios.cpp:64 SMKDANBETA_CDZ_SEARCH_PATTERN at 0xC00004"

  - name: uni-bioscd.rom
    path: "neocd/uni-bioscd.rom"
    system: snk-neogeo-cd
    required: false
    size: 524288
    note: "Universe BIOS 3.3, CDZ-based third-party multi-region BIOS"
    source_ref: "src/bios.cpp:68 UNIVERSE33_SEARCH_PATTERN at 0xC00150"